Remove duplicate values: unique

The unique filter removes duplicate values from a list, keeping only the first occurrence of each value. Unlike converting to a set, the unique filter preserves the original order of items. You can also deduplicate based on a specific attribute of each item.

This is useful when you have a list that may contain duplicates and you want to remove them while keeping the order intact. For example, you might collect states from multiple entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] and want to know the distinct states that exist, or you might merge multiple lists of devicesA device is a model representing a physical or logical unit that contains entities. and need to eliminate duplicates. The attribute parameter is especially helpful when working with lists of objects, letting you deduplicate by a specific property.

Usage

Here’s how to use this template function. Copy any example and adjust it to your setup.

{{ [1, 2, 2, 3, 1, 4] | unique | list }}

[1, 2, 3, 4]

Function signature

The signature is a technical summary of this template function. It shows the name of the function, the values (called parameters) it accepts, and what type of data each parameter expects (for example, a piece of text or a number).

Function parameters that have a = with a value after them are optional. If you leave them out, the default value shown is used automatically. Function parameters without a default are required.

unique(
    value: list,
    case_sensitive: bool = False,
    attribute: str | None = None,
) -> list

Function parameters

The following parameters can be provided to this filter.

Unique by attribute

Deduplicate a list of objects based on a specific attribute, keeping only the first object with each unique attribute value.

{{
  expand("group.all_sensors")
  | unique(attribute="state")
  | map(attribute="entity_id")
  | list
}}

["sensor.kitchen_temp", "sensor.bedroom_temp"]

Good to know

• Unlike Python’s standard behavior, this filter is case-insensitive by default. Pass case_sensitive=true if you want "On" and "on" treated as different values.
• Returns a generator, so pipe the result through list if you need to loop over it more than once or display it directly.
• The first occurrence of each value wins, preserving the original list order.

Try it yourself

Ready to test this? Open Developer tools > Template, paste the example into the Template editor, and watch the result update on the right. Edit the values to see how the function adapts to your own entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

More examples

Real scenarios where this function comes up in automations and templates. Copy any example and adapt it to your setup.

Find distinct states across entities

Get the unique state values from a group of entities.

{{
  expand("group.all_lights")
  | map(attribute="state")
  | unique
  | list
}}

["on", "off"]

Deduplicate a merged list

When combining entities from multiple sources, remove any that appear more than once.

{% set list1 = ["light.kitchen", "light.bedroom", "light.hall"] %}
{% set list2 = ["light.bedroom", "light.porch", "light.kitchen"] %}
{{ (list1 + list2) | unique | list }}

["light.kitchen", "light.bedroom", "light.hall", "light.porch"]

Case-sensitive deduplication

By default, unique is case-insensitive. Use case_sensitive=true to treat different cases as distinct values.

{{ ["On", "on", "OFF", "off"] | unique(case_sensitive=true) | list }}

["On", "on", "OFF", "off"]

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with your template and expected result, or share on our subreddit /r/homeassistant.

Related template functions

These functions work well alongside this one:

• Convert to set: set - Converts an iterable to a set, removing duplicate values.

• Sort a list: sort - Sorts the items in a list, with optional attribute-based and reverse sorting.

• Filter items by test: select - Filters a list, keeping only items that pass a given test.

• Group items by attribute: groupby - Groups a list of items by a common attribute, producing a list of (grouper, list) pairs.